Previous iteration was bad, because `Logger` instance was shared and
endpoints in different VUs were overriding each other.
New interface is much better, it supports logger extension in any
context with arbitrary fields.
```
const l = logging.new().withFields({endpoint: "my endpoint"});
...
l.withField("cid", container).info("not found");
```
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
